RF Performance of Nitrogen-Doped Production SRF Cavities for LCLS-II

Daniel Gonnella, Sebastian Aderhold, Andrew Burrill, Edward Daly, Kirk Davis, Anna Grassellino, Chuck Grimm, Timergali Khabiboulline, Frank Marhauser, Oleksandr Melnychuk, Sam Posen, Marc Ross (+7 others)
The Linac Coherent Light Source II (LCLS-II) requires 280 9-cell superconducting RF cavities for operation in continuous wave mode. Two vendors have previously been selected to produce the cavities, Research Instruments GmbH and Ettore Zanon S.p.a. Here we present results from manufacturing and cavity preparation for the cavities constructed at these two vendors for LCLS-II. We show how the cavity preparation method has been changed mid-production in order to improve flux expulsion in the
more » ... ulsion in the cavities and maintain high performance in realistic magnetic field environments (~5 mG). Additionally, we show that the nitrogen-doping process has been carried out successfully and repeatedly on over 70 cavities.
doi:10.18429/jacow-ipac2017-mopva128 fatcat:mug7qwtmsfa7tofd34xg6v35w4